Device for treating cigarette filter plugs



1967 SHIGEHIKO KATO 3,353,640

DEVICE FOR TREATING CIGARETTE FILTER PLUGS Filed April 2, 1964 INVENTOR ATTORNEYS United States Patent 3,358,640 DEVICE FOR TREATING CIGARETTE FILTER PLUGS Shigehiko Kata, Saijo, Japan, assignor to Kurashiki Rayon Company Limited, Kurashiki, Japan, a corporation of Japan Filed Apr. 2, 1964, Ser. No. 356,856 Claims priority, application Japan, Apr. 12, 1963, 38/ 19,178 2 Claims. (Cl. 11861) ABSTRACT OF THE DISCLOSURE It is necessary that cigarette filter plugs have a large filtering ability with a small pressure drop and a stable configuration and that they are manufactured by orienting crimped filaments in parallel along the longitudinal direction and adhering them at several points by adhesive. It is also most important that the adhered points are uniformly distributed all over the filaments. To this end, means are provided for treating fine powders of adhesive dispersed uniformly among a bundle of filament tow, and shaped and wrapped with paper, by treating the adhesive with a solvent to dissolve it and make it adhere to various filaments. In such a process if the adhesive powder remains in the state of powder the adhering is not effective, thus it is obvious that all the adhesive must be dissolved by a solvent or by heating it to a liquid state, then dried and solidified again, otherwise adhering points are not formed. On the other hand, if the adhesive is dipped into a liquid solvent the eflicient adhering characteristics of the powder process are not attained. According to the present invention the plug is treated with solvent vapor, thereby effectively utilizing the speciality of the powder adhesive to create positive adhering points in the plug. Since with the present invention a large quantity can be treated quickly in a small space and volume and safely operated, it provides tremendous advantages from the commercial point of view.

For a better understanding of the invention reference is taken to the accompanying drawing, showing a partial diagrammatic sectional elevation of the present invention for treating cigarette filter plugs.

Referring to the accompanying drawing, the device is provided with a solvent recovering means comprising an enclosed chamber 2 provided with a temperature regulating jacket 1 having a solvent reservoir 3 at its bottom, means 4 for heating the solvent, and an outlet 5 for the solvent vapor and hot air positioned at the top of the chamber. The cigarette filter plugs are arranged vertically in a plug box 6 so as to have their upper and lower cut ends exposed to the outside of the box 6. The boxes are arranged in the enclosed chamber in upper and lower layers. When the door (not shown) fitted to the temperature regulating jacket 1 is closed the chamber becomes enclosed. After such condition is attained at proper quantity of a suitable solvent appropriate 3,358,640 Patented Dec. 19, 1967 "ice to the kind of adhesives used is supplied to the solvent reservoir 3 through the feed inlet 8. The solvent is then heated by means of the heating device 4 so that it evaporates. At this moment, hot water is passed through the temperature regulating jacket 1 and the temperature in the enclosed chamber 2 is maintained at about the boiling point of the solvent. A proper amount of the solvent vapor liquefies when passing through the plugs to sufficiently wet them. If the temperature in the chamber is too low there is too much liquefied solvent which circulates into the plugs to prevent the favorable point adhesion. On the other hand, if the content of solvent vapor in the chamber is not enough, the treating time becomes longer, and, if the temperature is too high the solvent vapor does not substantially liquefy and the adhesive is not dissolved. Accordingly, it is desirable to maintain the temperature in chamber 1 at 1-3 C. lower than the boiling point of solvent used.

The device according to the invention provides that the chamber temperature be regulated by water or hot air in the temperature regulating jacket 1. In order to perfectly dissolve the adhesive powders after the solvent has completely evaporated it is necessary to maintain the plugs in the enclosed chamber at a proper temperature. The time for dissolving the adhesive powder can be shortened by raising the temperature. According to the present device, the plugs can be easily maintained at a suitable temperature by heating or cooling the jacket chamber by passing hot or cold water or air through the jacket. By quick dissolving the adhesive with solvent the operation can be safely performed. After evaporating the solvent remaining in the plug by heating the chamber it is driven out by blowing-in hot air through the inlet 9. According to the device of the invention, all operations as above described are carried out continuously in one chamber so that the operation is not only easy but it provides quick and safe treatment of a large quantity of plugs.

The heating device 4 for evaporating the solvent is preferably of such a type that the temperature can be regulated by the boiling point of the solvent and is soconstructed that water or other heating medium is introduced through the pipe 10 into the heating device 4 discharged through pipe 12, and heated by passing steam through the heat exchanger 11.

The door of the enclosed chamber should be tightly sealed by means of a packing made of a material resistant to the solvent and provided with a perfect locking means. The other feed inlet 8 for acetone, hot air inlet 9, outlet 5 of hot air and solvent and the pipes communicating to the enclosed chamber 2 should also be tightly sealed. With perfect sealing the loss of solvent and heat is eliminated and danger is avoided.

The plug receiving box 6 is provided at its bottom with gauze having smaller meshes than the diameter of the plug allowing it to freely pass the vapor, thereby avoiding any accumulation of solvent liquid on the bottom of the container. The plug receiving box may consist of a stack of boxes to be piled one on the other as shown in the drawing, may be put on stoppers fixed to the inside wall of the enclosed chamber 2 or may be expanded in the chamber. In any case, it is preferable that plugs in the upper and lower stages do not contact each other. It is convenient to construct a block of several receivers convenient for packing by combining the frame for packing plugs with a net-shaped receiver dish and packing it into the enclosed chamber. In order to pack plugs 7 into the plug receiving box 6 it is also convenient to make one side of the box 6 open and direct it upward by sitnating the box crosswise facilitating the packing of the piledup plugs.

The adhesive and solvent used for the manufacture of cigarette filter plugs by powder adhering process are starch, casein or polyvinyl alcohol, which use Water as its solvent, but in most cases powder of cellulose acetate, polymethylmethacrylate, polyvinyl acetate and the like high molecular weight substances may also 'be used as the adhesive and alcohol, acetone, benzene and the like as the solvent. For such solvents it is necessary to recover the solvent vapor in order to reduce the cost and the dangers involved. With the present invention there is no tendency of solvent vapor to leak out as all vapors are discharged through the exhaust outlet where it can be collected by directly connecting a cooler 13 and a solvent receiver 14. Since the exhaust from the hot air driving away the solvent does not contain a substantial amount of solvent it is not necessary to send it to the recovering devices, but it can be exhausted into the air through the independent exhaust pipe 15.

When the solvent in the solvent reservoir 3 is evaporated, the valve 16 is closed and the valve 17 is opened. Accordingly, the solvent vapor passing through the plugs is not delivered to the pipe 15 but is delivered to the cooler 13. When the evaporation of the solvent is interrupted and air is charged into the chamber, valve 17 is closed and the valve 16 is opened.

What I claim is:

1. A device for treating cigarette filter plugs containing powder adhesive and wrapped with paper, comprising an enclosed chamber, means for stacking said filter plugs in said chamber, a solvent reservoir provided in the bottom of said chamber, an outlet through the top of said chamber, heating means in the bottom of said chamber for vaporizing saidsolvent so as to cause said vaporized solvent to pass from said reservoir to the outlet of said chamber through said filter plugs thereby dissolving the powder adhesive in said plugs, a temperature regulating means surrounding said chamber and means located at the bottom of said chamber for blowing air into said chamber below said filter plugs to'pass the vaporized solvent out of said chamber to said outlet and set said adhesive.

2. A device as defined in claim 1 including a condenser connected to the outlet of said chamber for condensing said solvent vapor emitted through said outlet.

References Cited UNITED STATES PATENTS 942,150 12/1909 Tiemann 34-36 X 2,273,039 2/1942 Hudson 34-37 X 2,293,453 8/1942 Clark 3437 X 1,059,820 4/ 1913 Besemfelder 34-37 2,009,232 7/ 1935 Hood 11 86l X 2,535,087 12/ 1950 Munters 118-61 2,702,433 2/ 1955 Cohen 3'437 CHARLES A. WILLMUTH, Primary Examiner.

J. P. MCINTOSH, Assistant Examiner. 

1. A DEVICE FOR TREATING CIGARETTE FILTER PLUGS CONTAINING POWDER ADHESIVE AND WRAPPED WITH PAPER, COMPRISING AN ENCLOSED CHAMBER, MEANS FOR STACKING SAID FILTER PLUGS IN SAID CHAMBER, A SOLVENT RESRVOIR PROVIDED IN THE BOTTOM OF SAID CHAMBER, AN OUTLET THROUGH THE TOP OF SAID CHAMBER, HEATING MEANS IN THE BOTTOM OF SAID CHAMBER FOR VAPORIZING SAID SOLVENT SO AS TO CAUSE SAID VAPORIZED SOLVENT TO PASS FROM SAID RESERVOIR TO THE OUTLET OF SAID CHAMBER THROUGH SAID FILTER PLUGS THEREBY DISSOLVING THE POWDER ADHESIVE IN SAID PLUGS, A TEMPERATURE REGULATING MEANS SURROUNDING SAID CHAMBER AND 